Created by Ra's al Ghul as a means to purge evil, the organization would grow popular and under Ra's discipline would become powerful very quickly. After Ra's alliance with the All Caste, founding of Eth'Alth'Eban and creation of the Lazarus Pit he became immortal and stayed as the organization's leader for centuries. The League became so powerful that they were feared over the known world.
Over time the organziation became more secular, allowing nations to advance beyond their grip. In the late twentieth century, Ra's fathered a daughter, Talia al Ghul. This motivated him to try and make the organization powerful again. Though he failed at this, he did manage to set up several international bases across the continents. He also resurrected and recruited Tommy Merlyn to lead the Seven Men of Death, the League's elite strike team.
Ra's failure to make the League powerful prompted the Sensei and his followers to turn against the League. Though Ra's defeated Sensei, the damage was done and the League was fractured. This allowed Dr. Darrk to take many assassins and create his own League of Assassins. This splinter faction moved to Gotham City, raising the ire of the Batman. The Batman, who Ra's found to be Bruce Wayne, destroyed Darrk's League and turned his attention to the main faction. Though Ra's attempted to get Wayne to join the League, the latter's refusal to kill led him to once again fight and stop the League's expansion.
For years the League stayed silent, though they did resurrect and corrupt Jason Todd. They also trained Wayne's son, Damian, to be a killer. When Leviathan began to wage war against Batman Incorporated, Talia turned on her father. She consolidated the League into Levaithan and placed Ra's under a form of house arrest. After the Battle of Gotham City, Ra's regained control of the League and began to act out against Batman, sending Penumbra to Gotham. In the Battle of Nishapur, Ra's was again assumed dead, allowing Odysseus to manipulate Lady Shiva into making the League protect him. With Shiva in charge, she swore the allegiance of the League to Odysseus. The plans of Odysseus, however, were quickly thwarted when he was defeated by Deathstroke in Gotham City.
- Bronze Tiger - One of the highest ranking members.
- December Graystone - Formerly operated by the name Blood Mage.
- Lady Shiva - One of the highest ranking members.
- Ra's al Ghul - Founder and leader.
- Rictus - A Metahuman assassin.
- Ubu - Ra's al Ghul's loyal bodyguard.
- Dr. Darrk - Blackmailed into working for the League.
- Mystasia - Defected from the Nova Council.
- Lawman - Defected from the Noval Council.
- Snakebite - Defected from the Noval Council.
- Cheshire - One of Bronze Tiger's protoges.
- Sensei - Attempted to usurp Ra's al Ghul.
- Talia al Ghul - Went on to found Leviathan and invade the League.
- Tommy Merlyn - Joined Leviathan.
- Jason Todd - Became a renegade mercenary.
- Anya Volkova - Joined the fight against secret organizations
- Penumbra - Was banished by Ra's al Ghul.
- Odysseus - Benefactor of Shiva.
- Slade Wilson - Betrayed Ra's al Ghul.
- Jericho - Rescinded his oath.
- Rose Wilson - Rescinded her oath.
- Victor Ruiz - Killed by Slade Wilson just as he joined.